Old chemicals are back in battle against weeds
As farmers wage war on a worsening weed problem, they are being forced to enlist the aid of chemicals they once virtually abandoned.
Since 1996, Monsanto's Roundup weed-killing system has become the dominant approach in agriculture, changing the way American farmers grow commodity crops. In the past several years, though, American farmers have increasingly reported that glyphosate, the key ingredient in Roundup, isn't killing weeds. So once-popular chemicals such as "2, 4-D" and "dicamba" again have been called to duty.
"It's really ironic that in this day and age of genetic engineering we're going back to a herbicide from the 1940s," said Dean Riechers, an associate professor of weed physiology at the University of Illinois, referring to the chemical "2, 4-D." "It's the oldest herbicide we have, and it's going to become really popular again."
The ineffectiveness of glyphosate has left companies scrambling to come up with other options, but some farmers and environmentalists are concerned about health and environmental risks.
"There's a big push to come up with something new, and it's necessary," said Steve Smith, director of agriculture for Red Gold, an Indiana-based tomato grower and processor. "Monsanto did a terrible job with (stewardship of) glyphosate. They said: That's the only thing you need, on soybeans, on corn. It was cheap and easy, and that's all anyone used."
Smith, who testified in Congress, warning against 2, 4-D and its related weed killer, dicamba, is launching a nationwide campaign against the industry's efforts. His company, he claims, lost $1 million in revenue because of dicamba contamination.
"It's an entire fiasco," Smith said. "But now that it's here, we have to figure out how to fix it."
The industry is counting on that fix.
"The glyphosate system revolutionized agriculture," said Kenda Resler-Friend, of Dow AgroSciences, a Monsanto competitor. "But anything that's been used that much, it puts a lot of pressure on it."
Dow AgroSciences, based in Indianapolis, is one of a handful of companies trying to come up with a system that will combat weeds. The company is working on a engineering plants to be resistant to 2, 4-D, which will be used in combination with glyphosate. A corn product will be released in 2013, followed by soybeans in 2015.
"Our crystal ball was looking pretty clear," Resler-Friend said, noting that the company predicted problems with glyphosate and has been working on its new system for eight years.
Creve Coeur-based Monsanto is working with chemical giant BASF, makers of dicamba, on a dicamba-glyphosate system that will debut "mid-decade," in soybeans, then in cotton, followed by corn, the company said.
"They've got quite a bit of expertise," said Matt Helms, who is heading up the dicamba efforts for Monsanto, referring to BASF. "Jointly, we're working on different types of formulations, on next-generation formulations that will be even better."
In addition to the joint Monsanto-BASF effort and the Dow AgroSciences project, Bayer, Syngenta and DuPont are all working on new herbicide resistant seeds, too.
FUTURE CONCERNS
One problem, critics say, is that glyphosate was so effective that the industry stopped researching other chemicals, and now has few new chemicals in the pipeline. That will mean, they say, that farmers will increasingly use these new cocktails containing old, somewhat problematic chemicals.
"Conservative estimates of adoption would result in significant increase in herbicide use in soybean and cotton; disturbingly, through the use of older higher-use-rate herbicides," said David Mortensen, a weed ecologist with Pennsylvania State University, in a statement before a congressional subcommittee. "If glyphosate and 2, 4-D or dicamba are adopted in the way I expect they will (be), herbicide use in soybean would increase by an average of 70 percent in a relatively short time ..."
That, some worry, will mean that weeds will rapidly develop resistance to these new cocktails, too.
"These crops will have the same problems," said Bill Freese, of the Washington-based Center for Food Safety, a group critical of the biotechnology industry. "Then we'll have other herbicide-resistant crops, and they'll be resistant to four, five, six herbicides."
Critics also point to environmental concerns. Dicamba and 2, 4-D have a tendency to "drift" into neighboring fields, damaging nearby crops. "Some growers bought (Roundup Ready) crops to protect themselves against Roundup drift," Freese said. "Many will likely do the same with dicamba-resistant crops. This means paying more for pricey seeds even if you don't want to use that trait. Not fair."
The industry, however, says the new cocktails won't have the old problems.
"I wouldn't say dicamba has any greater risk to volatility or drift than any other chemistry," said Nevin McDougall, of BASF's crop protection division. "...We're working with Monsanto to develop best management practices to ensure that when growers use it for the first time, they're using the proper nozzles, ensuring applications are done with minimal wind speed and overall environmental conditions are favorable for on-target applications."
Dow AgroSciences says its developers are working to minimize problems with 2, 4-D. "This is a different 2, 4-D," Resler-Friend said.
As the new blends hit the market in coming years, the industry and researchers are keeping their fingers crossed that resistance won't be the problem it became with glyphosate.
"I'm hoping we can learn a lesson from what happened with glyphosate," University of Illinois' Riechers said. "I think it could happen, but with good stewardship, it shouldn't be that bad."
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Verfasst: Sonntag 5. Juni 2011, 12:09